Yesterday the sale was postponed for another month as a fourth bidder joined the pack chasing Western Australia’s crucial energy asset. The new bidder is thought to be the Prime Infrastructure Fund and its shareholder, Babcock & Brown, which may have joined Alinta in renewing its interest in the pipeline.

If Prime Infrastructure has rejoined the race it would be the third consortium in discussions with the pipeline's major shippers - Alcoa, Western Power and Alinta, while Alinta itself continues to assess its ownership position on the pipeline.

Alinta withdrew from the bidding race in February claiming that a lack of access to due diligence information had made it impossible to submit a bid. The company is also heavily in debt following its $1.690 million acquisition of Duke Energy's Australian interests.

At the time the ACCC also hinted that any ownership of the pipeline by Alinta would be need to be reviewed due to concerns of monopolisation of the WA market.

Protracted negotiations between each bidder and the individual shippers have been blamed for the extended deadline to August 25.

Two consortiums are openly conducting due diligence with Australian Pipeline Trust linking with Canada's Enbridge Inc, and the rival bidding group comprising Envestra and its shareholders Cheung Kong Infrastructure Holdings and Origin Energy.

The State Government is known to be increasingly concerned with the extended sales process as it wants the pipeline sold and expanded urgently so Western Power has sufficient gas to meet its power generation needs for the 2005-2006 summer peak.